* {
  margin: 0;
  padding: 0;
}

body {
  width: 100vw;
  min-height: 100vh;
  font-size: 16px;
}

input {
  box-sizing: border-box;
}

.btn {
  user-select: none;
  cursor: pointer;
}

.btn:active {
  box-shadow: 2px 2px 4px 6px rgba(0, 0, 0, .1);
}